Improvement in steam-engines



2 SheetswSheet l,

E,.`WYATT.

y STEAM ENGINE. No. 48,1379. Patented June 6 1,865.

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R. WYATI STEAM ENGINE.'

Patented June 6, 1865.

y UNITED PATENT OFFICE."-

noBER'r WYATT, on Bnoonnvn, mitm Assrenon tro HIMsELF AND w'. menen, sans; rasen.

IMPROVEMENT mv STEAM-'Encima Speciication forming part of Letters'. PatentzNc. 48,1219', datedd' une 6, 1865.

T o all whom 'it may concern.:

Beit known thai-1, RoBERgr WYATT, of the .city of Brooklyn, in the county of Kings and State of NewYork, have invented certain new and useful: Improvements in Steam-Engines andvI do hereby declare that th following is a full, clear, and exact description of the same, reference being had to the accempanyin g drawings', formingl part of this speciication, in Which-'- o Figure 1 is a central vertical section ot' an engine with my improx'ements. Fig. 2 is a transverse vertical section of the same in the plane indicated by the line a' a: in Fig. 1. Fig. 3 is a transversevertical sectionof Athe same in the plane indicated by the linefy y in Fig. 1. Fig. 4 is a face view of the threev valves.

Similar letters of reference indicate correspondin g parts in the several figures.

This'invention relates to compound reciprocating engines having a cylinder and piston such as arev described and claimed in John B.

BootsLetters Patent dated September 15,l

1863. In these engines, as described in the Letters Patent aforesaid, and as manufactured by Root, the crank-shaft passes through the center of one-of the cylinder-heads, the'crank is within the cylinder, and the crank-wrist works in a bearingin the inner pistomandthe consequence is that the crank-wrist becomes so heated when theengine is in operation as soon to wear outitselfanddthe bearing, even, in some cases, melting the bearing. i

With awview to remedy this defect a part of my invention consists in certain means, or a certain method, ofconnectin'g the two pistons with a crank outside the cylinder.

Another part of my invention'consists in a novelocombination of slide-valves for eifecting the induction and eduction of steam through the four ports of the cylinder to actupon 'the two pistons.

To enableothers skilled in the art to make and use my invention, I will proceed to describe its construction and operation- Ais the cylinder. Bis the outer piston, fitted to work horizontally' within the cylinder, and C is the inner piston, iitted to work vertically within the outer one, Vall substantially as described in Roots patent,hereinbefore referred to. The inner pistonis grooved and fitted with springs b b against the sides of the interior of the outer piston, and with packing-strips c c, Fig.- 1, pressed out by similar springs against they cylinder-heads A' and A2. The outer pisd, Fig. 2,of similar character, to keep'it,V steamtight between the cylinder-heads. The upper side of the cylinder is grooved and fitted 'with packing-strips e e, which are pressed downward by springs against the upper part of the outer piston, B., to prevent leakage between the piston and the top 'of the cylinder as the said piston wears down. Y

The inner piston, C, has firmly4 connected D,"wlii ch workslongitudinally through astu'- in g-box secured firmly to or constructed upon.

the length thereof. This stuiiing-box passes through a slot, f, in the top of the cylinder, long enough to permit the movement of the stufErng-box with the piston B, as the latter makes its stroke. This stuffing-box fits within an d. projects through a socket, Fit, provided in a sliding plate, F, which is fitted to a dovetail groove, g, extending the whole length ofthe exterior of the top of the cylinder. This sliding plate, moving parallel with the piston B, tends to keep the stnding-box and piston-rod upright in their horizontalmovement with the said piston. The smiling-box prevents leakage of steam around the piston-rod, and the packing strips d d prevent leakage through Lthe slotf.

G is the crank-shaft, arranged with-its vaxis perpendicular to the planes of movement of the pistons B and C iua position sufficiently elevated above the cylinder to permit the upper end ot' the piston-rod D to be connected `with" the wrist G2 of its crank G', and permit the revolution of the crank.. The said shaft is supported in this position in two bearings, one of which is on astaudard, H, erected upon the cylinder, and the other on a standard, I, erected on the bed-plate J with which the cylinder is cast, or to which it is otherwise irmlysecured.

The valve-chest K-of the engine, with which is cast with or bolted to the cylinder-head A2, and has communication with the cylinder by vpacking-strips a a, Fig. 2., pressed out `by ton is grooved and fitted with packing-striped with it by a mortise, t, tenon t','and pin t, or Y by any suitable means, ain upright piston-rod,

thel top of the outer piston, B, at the middle of the induction-pipe of the engine is connected,l

means of four passages, L L L2l L3, the inner ports, i' i3, otL' L3 communicating with the cylinder near the ends thereof, and outside ofthe pistonB, and the inner ports, i i3, of L L2 communicating with the cylinder Within the .piston B, close to the top and bottoin'of the said piston and outside of the piston C. This arrange mentof the inner ports is the same asin Roots engine, andthe induction and eduction of the steam to and from the cylinder, through the said ports, taking place in the same manner .as it does' in that engine, produces a similar L L2, to produce the upward and downward' reciprocating movement of the inner piston. N effects the induction and eductiou through the portvL, and N3 effects the induction and eduction through the port L3, the two latter valves operating to produce the horizontal reciprocating movement of the outer piston.

Springs 'u 'v are Aapplied in cavities u' w, at the end of the cylinder, to gradually check the movement of the outer piston, B, at the ends of the stroke, and so prevent any strain on the piston-rod. z

The valve M resembles an ordinary threeport slide-valve, such as is commonlyT used for reciprocating steam-engines, and works'in a similar manner over theouter ports, 0 o3, Figs. l, 3, and 4, of the passa-ges L L3, ,and over an 4nterinediate Aexhaust-port, @which communi'- eates lwith an exhaust-chamber, P, which is situated between the chest K and the cylinder, and with which the main educti'on-pipe ofthe engine is connected. The said valve is operated by an eccentric, Q, on the shaft G, the stemqof thesaid valve passing through a stuffing-box in the top ofthe chest K, and being connected with the rod Q5* ot' the said eccentric.

The valves N and N3 are arranged on oppo site sides of the valve M,'and are connected together by a yokepiece,lt,gwhich also serves to connect the two with the same stem r, passing through a stufiing-box in the topof the valve-chest. The valve N works over the outer'port,`o, of the passage L', and over an exhaust-port, s', Figs. 3 and 4, which communicates with the exhaust-chamber P; and the valve N3 works over the outer port, o3, of the exhaust-passage L3, and over an eXha-ustport, s3, Figs. 3 and 4, which com municates with the exhaust-chamber P. The exhaust-port s is below the port o', and the exhaust-port 83 below the port 03, and hence, though the valves Nand N3 are alike and connected together, the operation oi" one of the said valveslis the reverse ot' that of the other, each performing the induction of steam to the cylinder at one end While theother performs the eduction ofv steam trom the other end. The stem r yof the valves N and N3 is connected for operating the said valves with the rod Si* ot' an eccentric, S, on the crank-shaft G, the said eccentric being set'at right angles to the eccentric Q, and the two eccentrics being so set relatively to the crank G that the induction and A eduction ot' the steam to and from the cylinder, through the passages LL2 will commence as the crank arrives at the highest and lowest points in its revolution, and theinduction and eduction through the passages LL3 will commence as thecrank arrives at half-stroke-that is to say, inthe horizontal position oneither side of the shaft. l

What I ,claim as my invention, and desire to secure by Letters Patent, is-

1. Connecting 'the two pistons B C with a clank outside of the cylinder by means of a piston-rod, D, which is attached to the inner piston,-0,and passes throughthe outer piston, B, and which has a longitudinal movement with the inner piston, C, anda lateral movement with the two pistons B C, substantially as and for the purpose herein specified.

2. The starting-box E, through which the piston-rod D works, attached to theouter piston, B, and working'in' a slot, f, in the cyl'in der, substantially as and for the purpose herein stforth.

3. The sliding' plate F and its socket Eig-titting the stufng-box E and Working within'a groove or guide, g, on the exterior of the c'ylfor the` 'purpose ROBERT WrATT.

Witnesses: HENRY T. BRoWN,

WILLIAM LARDER. 

